Bicyclo(2,2,2)oct-5-ene-2,3-dicarboxylic anhydrides as herbicides



United States Patent 3,476,546 BICYCLO(2,2,2)OCT--ENE-2,3-DICARBOXYLIC ANHYDRIDES AS ,HERBICIDES Gwyneth M. Roberts, Doncaster, Victoria, Faye E. Butt,

North Balwyn, Victoria, Asbjorn Baklien, Kingsbury,

Victoria, JocelynM. Gregory, Croydon, Victoria, and

M Jan Kuiper, Wagga Wagga, New South Wales, Australia, assignors to Imperial Chemical Industries of Australia and New Zealand Limited, Melbourne, Victoria, Australia 3" No Drawing. Filed Dec. 2, 1965, Ser. No. 511,251 Claims priority, application Australia, Dec. 17, 1964,

' 53,063/ 64 Int. Cl. A0111 17/00, 9/24; C07d 5/32 US. CI. 71-88 Claims ABSTRACT OF THE DISCLOSURE Selective herbicidal compositions of matter containing as active ingredient a compound of the formula:

0 a R IRIE/ \R R R5- R1 R4 in wherein X and Y are oxygen; R is oxygen or Q=(IJ D, E and R to R inclusive, which may all be the same or different, are hydrogen, halogen or alkyl containing up to 3 carbon atoms and D and E may be linked to form a 6-membered ring whenever they stand for alkyl provided,

however, that R and R stand for hydrogen whenever R is a This invention relates to new compositions of matter having useful biological, particularly fungicidal and herbicidal properties.

Accordingly we provide new compositions of matter comprising as the biologically active ingredient at least one compound of the formula 3,476,546 Patented Nov. 4, 1969 same or different, are or Cl; Rf, R' D, E and R to R inclusive, which may all be the same or different, are hydrogen, halogen or alkyl and D and B may be linked to form a 6-membered ring whenever they stand for alkyl provided, however, that R and R stand for hydrogen whenever R is I v v r and an inert carrier therefor." The numbering of the positions of the substituents used throughout this specification whenever R is oxygen 01' NR is given in Formula Ib:

Bicyclo(2,2,2)oct-5-ene-2,3-dicarboxylic anhydride;

wherein X and Y, which may be the same or different, are 0 or S; R is selected: from the group consisting of 0, NR,

and

R is selected from the group consisting of hydrogen, alkyl, alkenyl, aryl, alkylamino, arylamino, dialkylamino, amino, thiazolyl, -SCZ wherein Z is Cl, Br or F and ACQCLCQ'CI: wherein Q and Q, which may b th w 5 methyl 7 isopropylbicyclo(2,2,2 ]oct 5 ene 2,3-

dicarboxylic anhydride;

on, g

O isoPr 3,6-dioxo-l l-sec.butyl*9 methyltricyclo-(6,2,2,0

dodeca-4,9-diene;

N.SCCl2.CHCl isoPr N-( l, 1,2,2-tetrachloroethyl -5-methyl-7-isopropylbicyclo(2,2,2) oct-5-ene-2,3-dicarboximide.

By inert carrier we mean either a liquid or a solid diluent used to obtain the desired concentration and to facilitate handling. 'For most purposes liquid formulations to be used in sprays are most convenient and among these again, aqueous liquid formulations are preferred. The latter may conveniently be prepared from emulsifiable solutions of the active compounds in organic solvents =by dissolving the active ingredients in a solvent which is non-toxic to the medium to 'be treated, particularly non-phytotoxic solvents e.g. in xylene, toluene, kerosene or the methylated naphthalenes, adding an emulsifier and/or wetting agent and emulsifying the solution in water. A typical emulsifiable concentration composition of this type would comprise 20% of the active ingredient, 40% kerosene, 35% xylene and 5% of an alkyl aryl polyether alcohol emulsifier, all quantities on a weight basis.

Alternatively our mixtures may also be formulated into dusts by combining them with solid inert carriers such as powdered chalk, talcs, kieselguhr, bentonite and other colloidal clays.

They may also be formulated as dispersible powders by milling the active ingredient to a fine powder, optionally together with an inert solid carrier as above disclosed and adding furthermore a dispersing agent finely ground with a colloidal clay.

Suitable emulsifying and dispersing agents are known from the prior art; anionic, cationic and non-ionic agents may be used. A suitable non-ionic emulsifier is e.g. the condensation product of nonylphenol with ethylene oxide available commercially under the trademark Lissapol N; suitable dispersing agents are e.g. the disodium salt of dinaphthlymethanedisulphonate, sodium lauryl sulphomate and the condensation product of alkylphenol with ethylene oxide available commercially under the trademark Lu'brol E and many others known in the art.

Our compositions are fungicides effective particularly against obligate fungi e.g. tobacco blue mould (Peronospora talracina), powdery mildew Podasphaem leucotricha (apples), Erysiph'e graminis (wheat) and Erysiphe cichoracaerum (pumpkins). Certain of our compositions have also shown post-emergence herbicidal activity and acaricidal activity. Thus we have found that certain isopropylmethylbicyclo(2,2,2)oct 5 ene-2,3-dicarboxylic anhydrides are highly selective herbicides; e.g. 2 chloro 6-methyl-8-isopropylbicyclo(2,2,2)oct-5-ene- 2,3-dicarboxylic anhydride kills mustard weed selectively in certain cereal and other crops without serious effect on the crop e.g. in wheat, rye, sorghum, rice and also in cotton, lucerne and beans, and N-(l,2,2,2-tetrachloroethylthio)-5 methyl-7-isopropylbicyclo(2,2,2)oct-5-ene- 2,3-dicarboximide kills mustard weed at dosages at which it does not damage wheat, oats or cotton. A further particularly preferred selective weedicidal formulation according to this invention comprises l-isopropyl-4- methyl-bicyclo(2,2,2)oct 5 ene-2,3,-dicarboxylic anhydride; we have found that it is extremely effective in combating barnyard grass in cereal crops at large and in rice in particular; it eradicates this weed at dosages of about 2 lb./acre and less while valuable crops such as oats and particularly rice, but also cotton, remain unaffected or slightly and only temporarily retarded at substantially higher dosages. The selectivity against barnyard grass in rice is particularly valuable since barnyard grass (Echinochloa crus-galli) is the most prevalent and troublesome weed in rice and is so similar to rice. It is difficult to distinguish from rice at the early stages of growth and therefore difficult to eradicate manually and also similar to rice in its response to chemical agents and therefore difficult to control chemically. Consequently to date only very few effective and selective agents against barnyard grass in rice have been found. Yet another compound, 2,3 dichloro 5-methyl-7-isopropylbicyclo(2,2,2)oct-S- ene-2,3-dicarboxylic anhydride exhibits moderate anthelmintic and tickicidal activity; 2,6-dirnethyl-8-isopropylbicyclo(2,2,2)oct-5-ene-2,3-dicarboxylic anhydride, 1-iso propyl 4-methylbicyclo(2,2,2)oct-5-ene-2,3-dicarboxylic anhydride and S-methyl-7-isopropylbicyclo(2,2,2)oct-5- ene-2,3-dicarboxylic anhydride exhibit some acaricidal activity.

Many of the active compounds of our new compositions of mater are new compounds. Accordingly we also provide new compounds according to Formula I wherein X, Y, R and R to R inclusive are as defined in claim 1 characterised in that at least one of the radicals X and Y is sulphur.

Furthermore we provide new compounds according to Formula I wherein X and Y are oxygen; R is R" and R, which may be the same or difi'erent, are hydrogen, halogen or alkyl; D' and E, which may be the same or different, are halogen or alkyl and, whenever D and E are alkyl groups, may be linked to form a 6-membered ring; and R to R inclusive are as defined in claim 1.

We also provide new compounds of Formula I wherein X, Y and R are oxygen, R to R inclusive are as defined in claim 1 and R and R which may be the same or different, are chlorine, bromine or methyl.

Particularly preferred new compounds suitable as active ingredients in our compositions are the compounds of the Formula I wherein X and Y and R are oxygen; R R R R R and R are hydrogen; R is methyl; R is isopropyl and R and R which may be the same or different, are selected from the group consisting of chlorine, bromine and methyl.

Other new compounds suitable as active ingredients of our compositions are the compounds according to Formula I wherein X and Y are oxygen; R is NR and R is alkyl, alkenyl, aryl, alkylamino, arylamino, dialkylamino, amino, thiazolyl, -SCZ wherein Z is Cl, Br or F and --SCQCl-CQ'C1 wherein Q and Q, which may be the same or different, are H or Cl; and R t R 0, Which may be the same or different, are hydrogen, alkyl or halogen.

Yet other new compounds are the compounds according to Formula I wherein X and Y are oxygen; R is NR; R is methyl, R is isopropyl and R R1 R R R R R and R are hydrogen and R is as dlefined in claim 1.

Preferred are the compounds in which R is methyl and R is isopropyl and R R to R inclusive, and R to R 1 l inclusive are hydrogen, and the compounds in which R is isopropyl and R is methyl and R R and R to R inclusive are hydrogen.

We also provide a process of manufacturing compounds of the Formula I as defined in column 1, which process comprises reacting 1,3-cyclohexadienes of the formula I R6 R R;

R R l R4 Formula II with a compound of the formula We have found furthermore that the above process is also operative when the substituents X, Y and R are as defined above and, in addition, when X and Y are oxygen,

R is NR and R and R to R inclusive are as defined above.

Compounds of Formula III include e.g. maleic thionoand dithionoanhydrides, thiomaleimides, dithiomaleimides and cyclopentene-3,5-dithiones.

The reaction is carried out with or without a solvent, at temperatures from 10 to 200 C. at atmospheric or higher pressures. Suitable solvents are e.g. benzene, toluene, ethanol, chloroform. The temperature is dependent on the type of reactants, e.g. 20-50-100150 C.

Suitable 1,3-cyclohexadienes are a-phellandrene, a-terpinene, l-methylcyclohexa-1,3-diene, Z-methylcyclohexa- 1,3-diene, S-methylcyclohexa 1,3 diene, l-isopropylcyclohexa-1,3-diene, 2-isopropylcyclohexa-1,3-diene, 5- isopropylcyclohexa-l,3-diene, Z-methyl-S-ethylcyclohexa- 1,3-diene, 2 methyl 5-sec.butylcyclohexa-1,3-diene, 1- chlorocyclohexa-1,3-diene, 2 bromocyclohexa 1,3-diene, 2,5 dichlorocyclohexa-l,3-diene, 1,3-dimethylcyclohexa- 1,3 diene l,3,5,54tetramethylcyclohexa-1,3-diene, 2,3- dichlorocyclohexa-1,3-diene.

A further process of the invention leading to compounds of the formula II X Formula IV comprises reacting a compound of the formula R R f 12 e.g. MeOH, EtOH. Alternatively in this process R may be methyl, R may be isopropyl and then M may also be hydrogen.

Yet another process of manufacturing compounds of the formula Formula V wherein X, Y and R to R inclusive are as defined above, comprises reacting a compound of the formula Y 1 II with a compound R Z where Z is halogen and R is as defined in connection with R above in the presence of an acid acceptor such as NaOH, KOH, NaOC H NaNH etc.

Yet another process for the manufacture of compounds of the formula Formula VI wherein X, R and R to R inclusive are as defined above, comprises reacting a compound of the formula R1 R, E 0 R RPE/ \R EXAMPLE 1 2-chloro 6-methyl-8-isopropylbicyclo (2,2,2) oct-5-ene-2,3-dicarboxylic anhydride A solution of chloromaleic anhydride (9.7 g.) and m-phellandrene (10 g.) in toluene (10 ml.) was heated in a sealed pressure tube at 135 C. for 3 hours. The cooled product was removed from the tube and distilled in vacuo to give a forerun consisting of toluene, a little unreacted chloromaleic anhydride and a-phellandrene followed by a main fraction of HP. -3/1Q.2 mm. Hg, which soon solidified. It was shown by nuclear magnetic resonance and infra-red spectroscopy and elemental analysis to be the required compound together with a small amount of the 3-chloro-isomer.

13 EXAMPLE 2 2,3-dichloro-S methyl-7-isopropylbicyclo(2,2,2) oct--ene-2,3-dicarboxylic anhydride Dichloromaleic anhydride (11.7 g.), a-phellandrene (9.5 g.) and toluene ml.) were reacted as described in Example 1. Distillation of the reaction product in vacuo gave a sublimate consisting of some unreacted dichloromaleic anhydride, a forerun consisting of toluene and unreacted a-phellandrene, and a main fraction of B.P. 135-8/ mm. Hg shown by nuclear magnetic resonance spectroscopy, infrared spectroscopy and elemental analysis to be the required compound.

EXAMPLE 3 i 9-methyl-1 l-isopropyl-S,6-dioxotricyclo (6,6,2,0

dodeca-4,9-diene p-Benzoquinone (32 g.) and a-phellandrene (41 g.) were heated under reflux in alcohol (80 ml.) for 2 hours. The alcohol was then distilled 01f to leave the crude product as a dark crystalline mass. Recrystallisation from petroleum ether gave the pure compound, M.P. 118 C.

EXAMPLE 4 5 -methyl7-isopropylbicyclo 2,2,2) oct-5 -ene-2,3-

dicarboxylic anhydride A solution of a-phellandreen (100 g.) and maleic anhydride (70 g.) in benzene (120 ml.) was heated at 50 C. for 1 hour. The solvent was then evaporated off and the product recrystallised from methanol, M.P. 127 C.

EXAMPLE 5 5-methyl-7-isopropylbicyclo(2,2,2)oct-5-ene- 2,3-dicarboximide 5-methyl-7-isopropylbicyclo(2,2,2)oct-5-ene 2,3 dicarboxylic anhydride (11.6 g.) and 80 m1. of alcohol saturated with ammonia at C. were heated in a carius tube at 150 C. for 1 hour. The cooled reaction product was removed from the tube and the solvent removed by evaporation. The almost pure product could be further purified by recrystallisation from benzene/petroleum ether, M.P. 141 C.

EXAMPLE 6 N- (trichlo romethylthio -7 -isop ropyl-S -methy1bicyclo (2,2,2)oct-5-ene-2,3-dicarboximide 1 5-methyl-7-isopropyl(2,2,2)oct-S-ene 2,3 dicarboximide (4.7 g.) and sodium hydroxide (0.8 g.) were dissolved in 40 ml. of water in a 100 m1. flask. To this solution was added trichloromethane chloride (3.7 g.). The flask was stoppered and shaken for 1 hour. The mixture was extracted with two 30 m1. portions of ether, the ether extract dried over sodium sulphate, filtered and the ether removed by distillation. This left the desired compound as a nearly colourless solid.

EXAMPLE 7 1-isopropyl-4-methylbicyclo(2,2,2)oct-5-ene-2,3-

. dicarboxylic anhydride a-Terpinene (50 g.) and maleic anhydride (35 g.) in

benzene (60 ml.) were heated under reflux for 1 hour.

Evaporation of the solvent yielded the crude compound which was purified by recrystallisation from methanol, M.P. 60 C.

EXAMPLE 8 N- (trifluoromethylthio -7-isopropyl-S-methylbicyclo (2,2,2)oct-5-ene-2,S-dicarboximide This was prepared as described in Example 6 using trifluoromethane sulphenyl chloride (2.75 g.) instead of trichloromethane sulphenyl chloride.

14 EXAMPLE 9 1-isopropyl-4-methylbicyclo(2,2,2j)oct-5-ene- 2,3-dicarboximide This was prepared from the corresponding dicarboxylic anhydride as described in Example 5, M.P. 155 C.

EXAMPLE 10 N-( 1,2,2,2-tetrachloroethylthio)-1-isopropyl-4- methylbicyclo(2,2,2)oct-5-ene-2,3-dicarboximide This was prepared from 1-isopropyl-4-methylbicyclo (2,2,2)oct-5-ene-2,3-dicarboximide and 1,2,2,2 tetrachloroethane sulphenyl chloride by the method described in Example 6.

EXAMPLE 11 S-methyl-7-isopropylbicyclo(2,2,2)oct-5-ene-2,3- dithiocarboximide EXAMPLE 1?.

N-trichloromethylthio-7-isopropyl-5-methylbicyclo (2,2,2)oct-5-ene-2,3-dithiocarboximide The product obtained in Example 11 was reacted with trichloromethane sulphenyl chloride as described in Ex ample 6 to give the desired compound.

EXAMPLE 13 7-sec.butyl-S-methylbicyclo(2,2,2))oct-5-ene- 2,3-dicarboxylic anhydride 2-methyl-5-sec.butyl-1,3-cyclohexadiene was reacted with maleic anhydride as described in Example 4 to yield the desired compound.

EXAMPLE 14 3,6-dioxo-11-sec.butyl-9-methyltricyclo(622,0 dodeca-4,9-diene 2 methyl 5 sec.butyl 1,3 cyclohexadiene and pbenzoquinone were reacted as described in Example 3 to give the desired compound.

EXAMPLE 15 N- (dimethylamino) -7-sec.butyl-S-methylbicyclo(2,2,2) oct-5-ene-2,3-dicarboximide 7 sec.butyl 5 methylbicyclo(2,2,2)oct 5 ene 2,3- dicarboxylic anhydride (12.4 g.) and 1,1 dimethylhydrazine (3.5 g.) in 50 ml. of alcohol were heated in a sealed tube at C. for 4 hours. Removal of solvent and excess 1,1-dimethylhydrazine in vacuo left the crude product which was purified by recrystallisation from methanol.

EXAMPLE 16 3,5-dioxo-l0-isoproyl-8-methyl-tricyclo(5,220) undec-S-ene 15 Cyclopentene-3,5-dione (19.2 g.) and et-phellandrene (28 g.) were dissolved in 100 ml. of benzene. The mixture was heated, with stirring, at 70 C. for 3 hours. The solvent and unreacted a-phellandrene were distilled off under reduced pressure and the residue recrystallised from meth- 10 grams of the ot-phellandrene-maleic anhydride adduct and 12 g. of hydrazine hydrate were heated in ethanol in a sealed tube at 150 C. for 1 hour. Solvent and unreacted hydrazine were removed by distillation in vacuo and the residue recrystallised from aqueous methanol, M.P. 89-

anol. 5 90 c.

EXAMPLE 17 3,5 -dioxo- 1-isopropyl-7-methyltricyclo 5 2,2,0)

undec-S-ene EXAMPLE 21 OH, H

25 g. of 5 methyl 7 isopropylbicyclo(2,2,2)oct- 5 ene 2,3 dicarboxylic anhydride (compound A), 2 chloro 6 methyl 8 isopropylbicyclo(2,2,2)oct- 5 ene 2,3 dicarboxylic anhydride (compound B), mom I 9 methyl 11 isopropyl 3,6 dioxotricyclo(6,2,2,0 dodeca 4,9 diene (compound C) and N trichloro- Cycl0pentene-3,5-d10ne e) and u-terpmene e) methylthio 5 methyl 7 isopropylbicyclo(2,2,2)octwere dissolved in 100 ml. of toluene and the solution 5 ene 23 dicarb0Ximide (compound D) h were i heated under reflux'fer 6 hours- Solvent and unreeeted solved in 70 ml. of toluene and 10 ml. of the surfactant P 9 were g d ofi under reduced P e r marketed under the registered trademark Triton X100 The residue was fllstllled 111 f yleld the trleyehe (isooctyl phenyl ether of polyethylene glycol) were added. compound as an 011 Whleh Soon solldlfied- The volume of each preparation was then made up to 100 ml. with further toluene. These formulations were EXAMPLE 18 then emulsified by mixing with water to concentrations N (p t01y1) s methyl 7 isopropylbicyclo(2,2,2) of 0.05% and 0.2% w./v. of active ingredient. Then oct 5 ene 2,3 dicarboximide 20? oi elach emulsion wefre 1sprtayed in a sgrzgy) cgabitntfi ono e oowin rou o ans:a 0o a A mixture of s'methyl'7isopropylbicyclo(23,2)71'5 wheat plants; a p ot of $0.5" tall oat giants; a box of eHe'Z3'diQarbOXYHC anhydride (23-4 and ptoluidme nine 4 week old tobacco plants and two 7" tall tomato (lo-7 m toluene (400 was heated under reflux plants. In addition, for comparison, dispersible powders a Dean and stark Q P F 6 hours- The toluene was of zineb (zinc ethylene-1,2-bisdithiocarbamate) and then removed by distillation in vacuo and the product re- Karathane (registered trademark for 2,4 dinitro 6 (2 cfystalhsed f Petroleum ether 804000 to octyl)phenyl crotonate) were sprayed onto further plants Yleld the deslred Compound as examples of fungicides well known to give highly effective control of the diseases shown in Table I. Twenty- EXAMPLE 19 four hours after spraying, the plants were infected in the N-dimethylamino-1-methyl-4-isopropylbicyclo(2,2,2) following manner. Tomatoes were inoculated with a conoct-5-ene-2,3-dicarboxirnide centrated spore suspension of Alternaria solani and to- 1 methyl 4 isopropylbicyclo(2,2,2)oct 5 e bacco with a concentrated spore suspension of Per- 2,3-dicarboxylic anhydride was reacted with a 20% molar onospom The Oat Seedlings Were inoculated y excess of 1,1-dimethylhydrazine in alcohol as described fillsting with P Puecinia cof'onata taken from in Example 5 to yield the desired compound infected plant material. Wheat seedl ngs were inoculated with Erysiphe gramims in a similar manner. After EXAMPLE 20 inoculation, the wheat was returned to the glass-house and the oats, tobacco and tomatoes were placed in a high 'f g i y humidity cabinet for 24 hours and then returned to the ene'23'd1car Oxlmlde glass-house. The tomatoes and wheat were assessed for disease and phytotoxic symptoms 4 days, the oats 8 days, after inoculation. The tobacco plants were returned to the humidity cabinet 6 days after inoculation for a period of 24 hours and then returned to the glass-house and assessed on the 7th day. The rating procedures for disease and phytotoxicity, and the results are given at the bottom of Table I.

TABLE I Puccim'u Eryeiphe Altemart'a Peronspora Coucencoronata gramt'nis aolanl tabacina 33231 1 Disease Phyto- Disease Phyto- Disease Phyto- Disease Phytow./v. toxity toxity toxity toxity Compound No.:

0.2 0 s 0 TB 0 sm 0 SLS B r 0.05 3 0 1 SLS l 0.2 o s 1 0 1 SLS 0 s C r 0.05 1 0 3 0 3 0 0 0 r 0.2 0 o 2 o 2 o 0 o D 4%?338388888 zineb $93 8 8:::::::::::::::::::: 3:33:33: st Karathene" 0.05 0 0 Phytotoxicity ratings: 0=No toxicity observed; TB=Tip burn; SLS=Slight scorch; S=M oderate scorch; Disease ratings: 0=0-25% diseased; 1=2550% diseased; 2=5075% diseased; 3=75100% diseased.

1 7 EXAMPLE 22 Chemicals designated A, B, C and D in Example 21 and 4,10-dimethyl 12 isopropyl-3,6-dioxtricyclo(6,2,2, 0 )dodeca-9,9-diene, designated E, were formulated and tested against the species shown in Table 11 according to the procedure described in Example 21, against which species they had shown promise in Example 21. In addition, the formulations of chemicals A and D which had 24 'hours before spraying with 30 adult mites of Tetranychus telarius per leaf. Four days after spraying the live and dead mites were counted and a percentage mortality figure was obtained by comparison with mortality occurring on plants sprayed with control emulsions, that is with an emulsion of the formulation described above omitting the test chemicals. Results are shown in Table III.

TABLE III shown activity against Eiysiphe graminis were sprayed on to apple seedlings which were later inoculated by dusting l0 Morta li g o i with spores of Podosphalsra leucorriclza and on to pump- Concentration, mites at 4 days kin seedlings later inoculated by dusting With spores of Percent after Spraymg Ersiphe cichoracearum. After inoculation, the apple and Compound No.1 pumpkin seedlings were returned to the glass-house and A 9? l; assessed for disease and phytotoxicity on the 8th day. The 0. a 97 scale for assessing phytotoxicity is shown at the bottom G Q03 0 of Table II. The amount of disease produced by Alter- 0.1 32 naria solani was assessed by counting the lesions on the 85 tomato seedlings and expressing the number as a percentage of those on control seedlings which did not receive 20 I3 35 fungicide. The amount of disease produced by Perono spora tobacina was assessed by counting the number of diseased seedlings from 4 boxes of nine seedlings each for EXAMPLE 24 each concentration of each fungicide and expressing the 20 g. of 1-isopr0pyl-4-methylbicyclo(2,2,2)o -5- number as a percentage of the diseased seedlings in 4 con- 25 2,3-dicarboxylic anhydride were dissolved in 70 mls. of trol boxes. For the other diseases, the amount of disease toluene. Then 9 mls. of the surfactant marketed under the produced was assessed on an arbitrary rating system from registered trademark Triton X100 (iso-octyl phenyl 0=no disease to 5=maximum disease. As reference standether of polyethylene glycol) were added, and the volume ards the well-known fungicides maneb (Manganous ethylmade up to 100 ml. with further toluene. This formulaene bisdithiocarbamate) and Karathane (registered tradetion was emulsified in water, and the emulsion was applied mark for 2,4-dinitro-6-(2 octyl)phenyl crotonate) were at a range of dilutions as shown inn Table IV through a tested in the same manner as compounds A, B, C and D small spraying boom on to boxes of soil in which various against the species of fungi shown in Table II, which are seedlings were growing. The boxes were passed under typical fungi for which they are used in practice. the boom on an endless belt moving at a pre-determined Results are given in Table II. constant speed.

TABLE II Puccim'a Erysiphe Podosphaera Erysiphe Peronosporu Altcrnaria Concencoronata gramints leucotricha cichoracaerum tubacina solam' $2135? Phyto- Phyto- Phyto- Phyto- Phyto- Phyto. w. v Disease toxicity Disease toxicity Disease toxicity Disease toxicity Disease toxicity Disease toxicity Compound No.: A

Karathane" 0. 2 0 Water Control 5 0 5 0 Phytotoxicity ratings: 0=No toxicity observed; S=Moderate scorch; SLS=Slight scorch; SVS=Severe scorch.

EXAMPLE 23 Compound A of Example 21, 2,6-dimethyl-8-isopropylbicyclo(2,2,2)oct-S-ene-Z,3-dicarboxylic anhydride (designated G in Table III) and l-isopropyll-methylbicyclo- (2,2,2)oct-5-ene-2,3 dicarboxylic anhydride (designated H in Table III) were formulated as described in Example 21. These formulations were emulsified in water to give concentrations of 0.3%, 0.1% and 0.3% w./v. of each active chemical. The emulsions were sprayed on to French After three weeks the plants were observed for the eifect of the chemical, and phytotoxicity ratings were carried out. The concentrations used and results for the chemical and for a control formulation, from which the active chemical was omitted, are shown in Table IV. In Table IV N indicates no effect, S indicates scorch, St indicates stunting, i.e., both S and St indicate relatively minor and often temporary elfects; K indicates that 25 to 50 of all plants treated, K indicates that 50 to of all bean plants with leaves cut to 1 inch square and infested 75 plants treated and K indicates that 75 to of all TABLE IV [Selective Herbieldal E fect of l-tsopropyl-4-rnethylbieyc1o(2,2,2)oct- -ene-2,3-dicarboxylic anhydride] Concentration of active ingredient in aqueous solution, w./v. percent Several formulations F F and F as defined below in this example of 1 isopropyl 4 methylbicyclo(2,2,2) oct 5 ene 2,3 dicarboxylic anhydride were mixed with water at concentrations shown below and applied through a small spraying boom onto boxes of soil in which there were growing alternating rows of rice and barnyard grass seedlings. The boxes were passed under the boom on an endless belt moving at a pre-determined constant speed so as to achieve application of a known dosage of pounds per acre of the active chemical. There were four boxes each containing rice and 20 barnyard grass seedlings for every rate of each of the formulations of the above-named test chemical and, for comparison, also four boxes each for two commercially available weedkillers, namely Stam (registered trademark) which is 3',4'-dichloropropionanilide and Ordram (registered trademark) which is ethyl-N-cycloheptylthiolcarbamate. Four further boxes were treated with the same quantities of water, solvent and surfactant mixture as described for formulation F but without the active ingredient, and four more boxes were treated with the quantities of water, solvents and surfactant described for formulation F but, again, without the active ingredient. The mean result obtained from the latter eight boxes was used as the control green weight. After spraying, all the boxes were placed in large metal trays in the glasshouse and subjected to periods of drying and flooding with water as required and indicated below. 3 Weeks after application of the chemical at the stage of development indicated in the tables, namely the 1- or 2- or 3-leaf stage respectively, the plants were cut at soil level and their green weights were determined. These green weights were then compared with the green weights of the control plants. The difference expressed as a percentage of the weight of the control plants is the percentage reduction in green weight listed in the tables, which shows to what extent the chemicals affected the growth of the rice and barnyard grass. Table V demonstrates the selective weedkilling effect of 1-isopropyl-4-methylbicyclo(2,2,2)oct- 5-ene-2,3dicarboxylic anhydride on barnyard grass and 20 rice when applied as post emergence treatment at an early stage (l-leaf stage) of the rice. The formulations were as follows:

50 g. of l isopropyl 4 methylbicyclo(2,2,2)oct-5- ene-2,3-dicarboxylic anhydride,

5 g. of the condensation product of one mole of an equimolar mixture of cetyland oleyl-alcohols with 10 moles of ethylene oxide made up to mls. with toluene and emulsified in water to give the concentration of the active ingredient stated in Table V.

40 g. of 1 isopropyl 4 n1ethylbicyclo(2,2,2)oct-5- ene-2,3-dicarboxylic anhydride,

9 g. of Teric N 13 (registered trademark, Imperial Chemical Industries of Australia and New Zealand Limited) a condensation product of 1 mole of nonylphenol with 9 moles of ethylene oxide, 6 g. of calcium dodecylbenzenesulphonate, made up to 100 mls. with a mixture of equal volumes of cyclohexanone and toluene, emulsified in water to concentrations of active ingredient stated in Table V.

40 g. of 1 isopropyl 4 methylbicyclo(2,2,2)oct-S- ene-2,3-dicarboxylic anhydride,

15 g. of Teric N 9 (registered trademark, Imperial Chemical Industries of Australia and New Zealand Limited) a condensation product of 1 mole of nonylphenol with 9 moles of ethylene oxide, made up to 100 mls. with cyclohexanone and diluted with water to the concentrations of the active ingredient shown in Table V.

The subsequent irrigation treatments were as follows:

A=sub-irrigation to base of plants.

B=plants flooded 24 hours after spraying to a depth of 1 /2" of water, maintained under water for 24 hours, allowed to dry at atmospheric conditions and after drying flooded again for 24 hours.

C=plants flooded 48 hours after spraying, to a depth of 1 /2 of water, maintained under water for 24 hours, allowed to dry at atmospheric conditions and then flooded again for 24 hours.

D=p1ants flooded 72 hours after spraying, to a depth of 1 /2" of water, maintained under water for 24 hours, allowed to dry at atmospheric conditions and then flooded again for 24 hours.

Similar treatments were also carried out at the 2-leaf and 3-leaf stage, but on the whole the percentage kill on the weed was somewhat lower at the 2-leaf and considerably lower at the 3-leaf stage i.e. treatment was most effective at the l-leaf stage. Results obtained for comparison with commercially available weedkillers for barnyard grass in rice, namely Stam and Ordram, are also given in Table V.

Since the latter are most effective at different developments of the rice plant, namely at the 2-leaf stage (Stam) and with pre-emergence treatment (O-rdram) respectively, figures for the commercial products are given at these most favourable stagesi.e. all compositions are compared at their respective most effective stages of application.

TABLE V the l-Leaf Stage] Treatment with active ingredient Percent reduction green Percent reduction green weight of rice using flooding weight 01 barnyard grass using Concentreatment flooding treatment tration, Rate,

w./v. lbs/acre A B C D A B C D Formulation:

Comparison with Commercially Available Product at 1 Leaf Stage Stam" 34 0. 2 2 25. 4 11. 1 0 33. 4 99. 4 96. 9 70. 6 99. 2

Comparison with Commercially Available Product at 3 Leaf Stage Starn" 34 0. 2 2 21. 9 0 6. 2 14. 1 100 98. 8 99. 7 99. 9

Comparison with Commercially Available Product-Pre-emergence application "Ordram 0. 2 2 0. 9 80. 7 0. 4 4 10. 9 90. 5

EXAMPLE 26 inclusive, which may all be the same or different, are

TABLE VI herbicidal e fect of 2-ch1oro-fi-methyl-8-isopropylbicyclo (2,2,2)oct-5-ene-2,3-dicarboxylic anhydride] Concentration of active ingredient in aqueous emulsion w./v. percent Rate of application of active ingredient in lbs/acre [Selective N Tip burn- N Ks K3 We claim:

1. A process for combatting the growth of weeds in growing cereal crops which comprises treating said crops with an eifective amount of a compound of the formula:

wherein X and Y are oxygen; R is oxygen and R to R hydrogen or alkyl containing up to 3 carbon atoms.

2. A process according to claim 1 wherein said active ingredient is 1 isopropyl 4 methy1bicyclo(2,2,2)oct- 5-ene-2,3dicarboxylic anhydride.

3. A process of combatting the growth of barnyard grass weed in rice crops according to claim 1, which process comprises firstly treating said crops with a composition containing 1 isopropyl 4 methylbicyclo (2,2,2)oct 5 ene 2,3 dicarboxylic anhydride, said composition being applied post-emergence in concentrations of between 2 to 4 pounds of active ingredient per acre, secondly flooding said crop at least once to a depth of 1 /2 inches with water 24 to 72 hours after treatment, thirdly maintaining the water at flood level for 24 hours after flooding and fourthly allowing the water to evaporate.

References Cited UNITED STATES PATENTS 1,944,731 1/1934 Diels et al. 260123 2,237,356 4/1941 Merrill 16730 2,507,207 5/ 1950 Hyman.

2,524,145 10/1950 Tawney 260-326 2,556,664 6/1951 Smith et al. 71-95 Re. 24,435 2/ 1958 Gilbert et al.

3,122,560 2/1964 Rigterink 7195 3,138,615 6/1964 Bluestone 71-95 3,198,811 8/1965 Weil 7188 3,320,270 5/1967 Grogan et al. 260-3068 3,326,934 6/1967 Akamatsu et al. 260-325 1,993,025 3/1935 Peterson et al.

2,328,567 9/ 1943 Matthews et al.

3,346,597 10/1967 De Acetis 3,334,991 8/1967 Hageman et al. 71-88 OTHER REFERENCES McCutcheon, Detergents & Emulsifiers 1963 Annual (1963).

LEWIS GOTTS, Primary Examiner G. HOLLRAH, Assistant Examiner US. Cl. X.R. 

